Just got a Weatherby 20ga SA-08. Still learning how the thing works. I'm new to shotguns. My only experience was 6 boxes of 12 ga at the last Shoot & Hoot. I'm sure my issue involves operator error. It's intermittent and very annoying. Went to the range to run a couple boxes through it to make sure it worked. I have the light load piston installed and the gun cycles flawlessly when fired. I have not removed the plug from the magazine, so I can load 2 + 1. That's what I was doing at the range. I fired two boxes, so about 16 sets of 3. My problem occurs while loading. With the action open, I put one shell in the chamber. I hit the slide release button on the right side. Slide closes solidly. I turn the gun over and put two more shells in the magazine. So far so good. Next step is supposed to be pushing the carrier lock button on left side back to lock the carrier and allow rounds in the magazine to be fed as needed. About 5 or 6 times, the carrier lock button would not move. I had to unload the shotgun completely and start the process over again. Once I had to repeat the process 2 times before the carrier lock button behaved correctly. What am I doing wrong?